Cumulative energy imbalance in the pediatric intensive care unit: role of targeted indirect calorimetry

Variation in metabolic demand following severe pediatric traumatic brain injury: A case review

A traumatic brain injury (TBI) is one of the most common pediatric traumas among children in the United States. Appropriate nutrition support, including the initiation of early enteral nutrition, within the first 48 h after injury is crucial for children with a TBI. It is important that clinicians avoid both underfeeding and overfeeding, as both can lead to poor outcomes. However, the variable metabolic response to a TBI can make determining appropriate nutrition support difficult. Because of the dynamic metabolic demand, indirect calorimetry (IC) is recommended, instead of predictive equations, to measure energy requirements. Although IC is suggested and ideal, few hospitals have the technology available. This case review discusses the variable metabolic response, identified using IC, in a child with a severe TBI. The case report highlights the ability of the team to meet measured energy requirements early, even in the setting of fluid overload. It also highlights the presumed positive impact of early and appropriate nutrition provision on the patient's clinical and functional recovery. Further research is needed to investigate the metabolic response to TBIs in children and the impact optimal feedings based on the measured resting energy expenditure have on clinical, functional, and rehabilitation outcomes.

Measuring Energy Requirements of Traumatic Brain Injury Patients in Pediatric Intensive Care With Indirect Calorimetry: A Comparison With Empiric Methods

OBJECTIVES

Energy requirements following moderate or severe pediatric traumatic brain injury (TBI) have not been fully elucidated. Indirect calorimetry (IC) is the gold standard for measuring resting energy expenditure (MREE) in PICU. However, technical complexity limits its use. We aimed to determine whether MREE differs from standard of care energy estimation and delivery in a cohort of pediatric patients following moderate to severe TBI during PICU admission.

DESIGN

Retrospective case series study.

SETTING

Single-center, 16-bed general PICU in Canada between May 2011 and January 2019.

PATIENTS

Children (0-18 yr) admitted to a PICU for moderate (Glasgow Coma Scale [GCS] 9-12) to severe TBI (GCS < 9) and had an IC study performed while mechanically ventilated.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

During the study period, 245 patients were admitted with the diagnosis of trauma with TBI. The study includes a convenience sample of 26 patients with severe ( n = 23) and moderate ( n = 3) TBI who underwent a total of 34 IC measurements. MREE varied considerably from 29% to 144% of predicted energy expenditure. Using Bland-Altman comparative analysis, neither Schofield nor World Health Organization predictive equations were in agreement with MREE. Only one measurement revealed that the patient was appropriately fed (energy provided in nutrition support was within 10% of MREE); 10 (38%) measurements revealed overfeeding and 15 (58%) underfeeding at the time of testing.

CONCLUSIONS

The present study adds to the small body of literature highlighting the limitations of predictive equations to evaluate energy requirements following moderate to severe pediatric TBI. IC, when feasible, should be used as the preferred method to orient PICU teams to feed such vulnerable patients.

Macronutrient and Micronutrient Intake in Children with Lung Disease

This review article aims to summarize the literature findings regarding the role of micronutrients in children with lung disease. The nutritional and respiratory statuses of critically ill children are interrelated, and malnutrition is commonly associated with respiratory failure. The most recent nutrition support guidelines for critically ill children have recommended an adequate macronutrient intake in the first week of admission due to its association with good outcomes. In children with lung disease, it is important not to exceed the proportion of carbohydrates in the diet to avoid increased carbon dioxide production and increased work of breathing, which potentially could delay the weaning of the ventilator. Indirect calorimetry can guide the process of estimating adequate caloric intake and adjusting the proportion of carbohydrates in the diet based on the results of the respiratory quotient. Micronutrients, including vitamins, trace elements, and others, have been shown to play a role in the structure and function of the immune system, antioxidant properties, and the production of antimicrobial proteins supporting the defense mechanisms against infections. Sufficient levels of micronutrients and adequate supplementation have been associated with better outcomes in children with lung diseases, including pneumonia, cystic fibrosis, asthma, bronchiolitis, and acute respiratory failure.

Feeding Pathway for Children on High Flow Nasal Cannula Decreases Time to Enteral Nutrition

High Flow Nasal Cannula (HFNC) is commonly used for children with respiratory failure, yet no standardized guidelines exist on how to initiate, escalate, and maintain enteral nutrition (EN) for these patients. EN in critically ill children is associated with decreased hospital length of stay, decreased ventilator days, and fewer acquired infections. We aimed to decrease the mean time to EN initiation by 50% after the start of HFNC in 6 months.

METHODS

This quality improvement project used the Model for Improvement to inform interventions. A multidisciplinary team created an EN pathway for critically ill patients on HFNC. We conducted Plan-Do-Study-Act cycles related to implementing a standardized pathway for EN on HFNC. The primary outcome was time to EN initiation once on HFNC. Secondary outcomes were time to goal caloric EN, duration of HFNC, and adverse events. Outcomes were plotted on statistical process control charts and analyzed for special cause variation between baseline and intervention periods.

RESULTS

We included 112 patients in the study. Special cause variation occurred for both primary and secondary outcomes. The mean time to EN initiation decreased from 24.6 hours to 11.7 hours (47.5%). Mean time to goal feeds decreased from 25.8 hours to 15.1 hours (58.5%). Mean HFNC duration did not show any special cause variation. There were no episodes of aspiration.

CONCLUSION

Implementation of a standardized pathway for EN on patients receiving HFNC resulted in decreased time to initiation of EN and time to goal caloric EN with no significant increase in adverse events.

Nutritional Considerations for the Neonate With Congenital Heart Disease

The importance of nutrition in managing critically ill infants with congenital heart disease (CHD) is foundational to optimizing short- and long-term health outcomes. Growth failure and malnutrition are common in infants with CHD. The etiology of growth failure in this population is often multifactorial and may be related to altered metabolic demands, compromised blood flow to the intestine leading to nutrient malabsorption, cellular hypoxia, inadequate energy intake, and poor oral-motor skills. A dearth of high-quality studies and gaps in previously published guidelines have led to wide variability in nutrition practices that are locally driven. This review provides recommendations from the nutrition subgroup of the Neonatal Cardiac Care Collaborative for best evidence-based practices in the provision of nutritional support in infants with CHD. The review of evidence and recommendations focused on 6 predefined areas of clinical care for a target population of infants &lt;6 months with CHD admitted to the ICU or inpatient ward. These areas include energy needs, nutrient requirements, enteral nutrition, feeding practice, parenteral nutrition, and outcomes. Future progress will be directed at quality improvement efforts to optimize perioperative nutrition management with an increasing emphasis on individualized care based on nutritional status, cardiorespiratory physiology, state of illness, and other vulnerabilities.

External Validation with Accuracy Confounders of VCO2-Derived Predicted Energy Expenditure Compared to Resting Energy Expenditure Measured by Indirect Calorimetry in Mechanically Ventilated Children

Optimal energy provision, guided by measured resting energy expenditure (REE) and determined by indirect calorimetry (IC), is fundamental in Intensive Care Units (ICU). Because IC availability is limited, methods to predict REE based on carbon dioxide production (VCO2) measurements (REEVCO2) alone have been proposed as a surrogate for REE measured by IC (REEIC). The study aimed at externally and internally validating the accuracy of the REEVCO2 as an alternative to REEIC in mechanically ventilated children. A ventilator’s integrated gas exchange module (E-COVX) was used to prospectively measure REEIC and predict REEVCO2 on 107 mechanically ventilated children during the first 24 h of admission. The accuracy of the REEVCO2 compared to REEIC was assessed through the calculation of bias and precision, paired median differences, linear regression, and ROC analysis. Accuracy within ±10% of the REEIC was deemed acceptable for the REEVCO2 equation. The calculated REEVCO2 based on respiratory quotient (RQ) 0.89 resulted in a mean bias of −72.7 kcal/day (95% limits of agreement −321.7 to 176.3 kcal/day) and a high coefficient of variation (174.7%), while 51.4% of the calculations fell outside the ±10% accuracy rate. REEVCO2 derived from RQ 0.80 or 0.85 did not improve accuracy. Only measured RQ (Beta 0.73, p < 0.001) and no-recorded neuromuscular blocking agents (Beta −0.13, p = 0.044) were independently associated with the REEVCO2−REEIC difference. Among the recorded anthropometric, metabolic, nutrition, or clinical variables, only measured RQ was a strong predictor of REEVCO2 inaccuracy (p < 0.001). Cutoffs of RQ = 0.80 predicted 89% of underestimated REEIC (sensitivity 0.99; specificity 0.89) and RQ = 0.82 predicted 56% of overestimated REEIC (sensitivity of 0.99; specificity 0.56). REEVCO2 cannot be recommended as an alternative to REEIC in mechanically ventilated children, regardless of the metabolic, anthropometric, or clinical status at the time of the evaluation.

A methodological and clinical approach to measured energy expenditure in the critically ill pediatric patient

The metabolic response to injury and stress is characterized initially by a decreased energy expenditure (Ebb phase) followed by an increased metabolic expenditure (Flow phase). Indirect calorimetry is a methodology utilized to measure energy expenditure and substrate utilization by measuring gas exchange in exhaled air and urinary nitrogen. The use of indirect calorimetry in critically ill patients requires precise equipment to obtain accurate measurements. The most recent guidelines suggested that measured energy expenditure by indirect calorimetry be used to determine energy requirements. This article reviews the methodological and clinical use of indirect calorimetry in critically ill pediatric patients.

Is Undernutrition Associated With Deterioration of Outcomes in the Pediatric Intensive Care Unit (PICU): Systematic and Meta-Analysis Review

BACKGROUND AND AIM

Undernutrition (UN) may negatively impact clinical outcomes for hospitalized patients. The relationship between UN status at pediatric intensive care unit (PICU) admission and clinical outcomes is still not well-reported. This systematic meta-analysis review evaluated the impact of UN at admission to PICU on clinical outcomes, including mortality incidence, length of stay (LOS), and the need for and length of time on mechanical ventilation (MV).

METHODS

A search was conducted using relevant and multi-medical databases from inception until January 2022. We considered studies that examined the link between UN at PICU admission and clinical outcomes in patients aged 18 years or younger. Pooled risk difference estimates for the PICU outcomes were calculated using a random-effects model.

RESULT

There were a total of 10,638 patients included in 17 observational studies; 8,044 (75.61%) and 2,594 (24.38%) patients, respectively, were normal-nourished (NN) and undernourished (UN). In comparison to NN patients, UN patients had a slightly higher risk of mortality (RD = 0.02, P = 0.05), MV usage (RD = 0.05, P = 0.02), and PICU LOS (RD = 0.07, P = 0.007). While the duration of MV was significantly longer in UN than in NN (RD = 0.13, P < 0.0001). Sensitivity analysis of UN classification cohorts with a z-score < -2 or in the 5%, patetints age up to 18 years, and mixed diagnose for PICU admission demonstrated a 6-fold increase in the probability of PICU LOS in UN patients compared to NN patients (RD = 0.06, 95% CI = 0.01, 0.12). UN patients have a higher risk of MV usage RD = 0.07, 95% CI = 0.00, 0.14) in studies involving cohorts with a mixed primary diagnosis for PICU admission.

CONCLUSION

In PICU, UN is linked to mortality incidence, longer PICU stay, MV usage, and duration on MV. The primary diagnosis for PICU admission may also influence clinical outcomes. Determining the prevalence of UN in hospitalized patients, as well as the subgroups of patients diagnosed at the time of admission, requires more research. This may help explain the relationship between nutritional status and clinical outcomes in PICU patients.

Metabolism and energy prescription in critically III children

Optimal nutrition therapy can positively influence clinical outcomes in critically ill children. Accurate assessment of nutritional status, metabolic state, macronutrient requirements and substrate utilization allows accurate prescription of nutrition in this population. In response to stress and injury, the body undergoes adaptive physiologic changes leading to dysregulation of the inflammatory response and hyperactivation of the inflammatory cascade. This results in a global catabolic state with modification in oxygen consumption and macronutrient metabolism. A comprehensive understanding of the metabolic response is essential when prescribing nutritional interventions aimed to offset the burden of this adaptive stress response in the critically ill. In this narrative review we aim to provide a comprehensive review of the physiologic basis, recent literature and some emerging concepts related to energy expenditure and the practical aspects of energy delivery in the critically ill child. Based on the unique metabolic characteristics of the critically ill child, we aim to provide a pragmatic approach to providing nutrition therapy.

Timing of parenteral nutrition is associated with adequacy of nutrient delivery and anthropometry in critically ill children: A single-center study

BACKGROUND

The optimal timing of supplemental parenteral nutrition (PN) use in the pediatric intensive care unit (ICU) is unclear. We aimed to describe patterns of PN use in the ICU and the association between the timing of PN initiation and macronutrient delivery and anthropometry.

METHODS

We enrolled patients (aged <18 years) with an ICU stay >3 days were started on PN in the ICU. Initiation within 48 hours of admission was deemed as early, and duration <5 days was deemed as short. We used multivariable analysis to examine the association between PN timing and macronutrient delivery adequacy (percentage of the prescribed target that was actually delivered) and weight-for-age z-score (WAZ) over hospital stay.

RESULTS

Ninety-five patients were included. Median (interquartile range [IQR]) time to initiate PN was 4 (1, 6) days, and in 33%, PN was initiated early. Median (IQR) PN duration was 8 (5, 14) days, and in 16.8%, duration was short. Median (IQR) adequacies for total energy and protein delivery were 55% (40, 74) and 72% (44, 81) in the early PN group compared with 29% (3, 50) and 31% (4, 47), respectively, in the late PN group (P < .001). The late PN group had a 0.50-unit greater decline in mean WAZ compared with the early PN group (95% CI, 0.11-0.89; P = .012).

CONCLUSION

Late PN initiation was associated with significantly lower adequacy of macronutrient delivery and greater decline in WAZ in critically ill children. The relationship between PN timing patient outcomes must be further examined.

Personalized nutrition approach in pediatrics: a narrative review

Dietary habits represent the main determinant of health. Although extensive research has been conducted to modify unhealthy dietary behaviors across the lifespan, obesity and obesity-associated comorbidities are increasingly observed worldwide. Individually tailored interventions are nowadays considered a promising frontier for nutritional research. In this narrative review, the technologies of importance in a pediatric clinical setting are discussed. The first determinant of the dietary balance is represented by energy intakes matching individual needs. Most emerging studies highlight the opportunity to reconsider the widely used prediction equations of resting energy expenditure. Artificial Neural Network approaches may help to disentangle the role of single contributors to energy expenditure. Artificial intelligence is also useful in the prediction of the glycemic response, based on the individual microbiome. Other factors further concurring to define individually tailored nutritional needs are metabolomics and nutrigenomic. Since most available data come from studies in adult groups, new efforts should now be addressed to integrate all these aspects to develop comprehensive and-above all-effective interventions for children. IMPACT: Personalized dietary advice, specific to individuals, should be more effective in the prevention of chronic diseases than general recommendations about diet. Artificial Neural Networks algorithms are technologies of importance in a pediatric setting that may help practitioners to provide personalized nutrition. Other approaches to personalized nutrition, while promising in adults and for basic research, are still far from practical application in pediatrics.

Nutritional status, intake, and outcomes in critically ill children with bronchiolitis

BACKGROUND

Optimal nutrition in children with severe bronchiolitis remains poorly described. We aimed to describe nutritional status and practices in children with severe bronchiolitis requiring admission to the pediatric intensive care unit (PICU), and explore their associations with outcomes.

METHODS

We conducted a retrospective study on patients with bronchiolitis requiring PICU stay from 2009 to 2014. Demographics, medical data, and baseline weight-for-length Z-scores (WLZ) were collected. In patients requiring more than 48 hours of PICU stay, nutritional intake data in the first 3 days of PICU stay were collected. Underfeeding and overfeeding were defined as the median energy intake of less than 80% and more than 120% of requirements, respectively. Protein adequacy was defined as intake of more than 1.5 g/kg/d. Primary and secondary outcomes of interest were the duration of PICU stay and mechanical ventilation (MV), respectively.

RESULTS

Seventy-four patients were included, with a median PICU stay of 4.9 days (interquartile range 2.0-8.2). Low WLZ at baseline was associated with longer duration of PICU stay (adjusted β: 4.33 [95% confidence interval [CI], 0.49-8.18]; P = .028) and MV days (adjusted β: 4.87 [95% CI, 1.56-8.18]; P = .008) compared to appropriate WLZ. In patients with ≥48 hours PICU stay, protein adequacy was significantly associated with greater PICU (adjusted β coefficient, 6.35 [95% CI, 1.66-11.0]; P = .009) and MV days (adjusted β coefficient, 5.22 [95% CI, 1.06-9.38]; P = .015).

CONCLUSION

Among bronchiolitis patients admitted to the PICU, low WLZ at admission was associated with a longer duration of PICU stay and MV. Protein adequacy was associated with longer PICU and MV days in children with ≥48 hours of PICU stay.

Review of Outcomes Used in Nutrition Trials in Pediatric Critical Care

BACKGROUND

Generating robust evidence within pediatric intensive care (PIC) can be challenging because of low patient numbers and patient heterogeneity. Systematic reviews may overcome small study biases but are limited by lack of standardization in outcome measures and their definition. Trials of nutrition interventions in PIC are increasing; thus, we wanted to examine the outcome measures being used in these trials.

OBJECTIVE

Our objective was to systematically describe outcome measures used when a nutrition intervention has been evaluated in a PIC randomized controlled trial.

METHODS

A systematic literature review of all studies involving a PIC trial of a nutrition intervention was undertaken from January 1, 1996, until February 20, 2018.

RESULTS

Twenty-nine trials met the criteria and were reviewed. They included a total of 3226 patients across all trials. Thirty-seven primary outcomes and 83 secondary outcomes were found. These were categorized into PIC-related outcomes (infection, intensive care dependency, organ dysfunction, and mortality) and nutrition outcomes (energy targets, nutrition parameters, and feeding tolerance). We found large variation in the outcome measures used. Outcome domains of energy targets, feeding tolerance, and infection were not adequately defined.

CONCLUSIONS

Considerable variation in the outcome measures chosen and their definitions exist within PIC nutrition trials. Optimal nutrition outcomes for PIC must be agreed upon and defined, specifically domains of nutrition efficiency, nutrition tolerance, and non-nutrition PIC outcomes. The next step is to conduct an international Delphi study to gain expert consensus and develop a core outcome set to be reported in future pediatric nutrition trials.

Peptide nutrient-energy dense enteral feeding in critically ill infants: an observational study

BACKGROUND

Enteral feeding is challenging in critically ill infants. Target intakes are often not achieved as a result of fluid restriction, procedural interruptions and perceived enteral feeding intolerance. In those infants perceived to have poor feeding tolerance, the use of a peptide nutrient-energy dense enteral feed (PEF) may improve nutritional intake and minimise feeding interruptions as a result of gastrointestinal symptoms. The aim of this observational study was to characterise the use of a PEF amongst critically ill infants in two paediatric intensive care units (PICUs).

METHODS

Records from critically ill infants aged <12 months admitted to two PICUs were retrospectively reviewed with a PICU length of stay (LOS) ≥ 7 days. Achievement of nutritional targets for the duration of PEF was reviewed. Gastrointestinal symptoms, including gastric residual volume, constipation and vomiting, were evaluated as tolerance parameters.

RESULTS

In total, 53 infants were included, with a median age on admission of 2.6 months. Median admission weight was 3.9 kg in PICU-1 and 4.7 kg in PICU-2. Median (interquatile range) energy intake in PICU-1 and PICU-2 was 68 (47-92) and 90 (63-124) kcal kg^-1 , respectively, and median (interquatile range) protein intake 1.7 (1.1-2.4) g kg^-1 and 2.5 (1.6-3.2) g kg^-1 , respectively. Feeding was withheld because of feeding intolerance in one infant (4%) on two occasions in PICU-1 for 2.5 h and in two infants (7%) on two occasions in PICU-2 for 19.5 h. Gastric residual mean (SD) volumes were 3.5 (5.4) mL kg^-1 in PICU-1 and 16.9 (15.6) mL kg^-1 in PICU-2.

CONCLUSIONS

Peptide nutrient-energy dense feeding in infants admitted to the PICU is feasible, well tolerated and nutritional targets are met. However, with this study design, it is not possible to draw any conclusions regarding the benefit of PEF over standard PE feed in critically ill children and future work is required to clarify this further.

Modification of Nutrition Therapy During Continuous Renal Replacement Therapy in Critically Ill Pediatric Patients: A Narrative Review and Recommendations

Introduction

Nutrition is an important part of treatment in critically ill children. Clinical guidelines for nutrition adaptations during continuous renal replacement therapy (CRRT) are lacking. We collected and evaluated current knowledge on this topic and provide recommendations.

Methods

Questions were produced to guide the literature search in the PubMed database.

Results

Evidence is scarce and extrapolation from adult data was often required. CRRT has a direct and substantial impact on metabolism. Indirect calorimetry is the preferred method to assess resting energy expenditure (REE). Moderate underestimation of REE is common but not clinically relevant. Formula‐based calculation of REE is inaccurate and not validated in critically ill children on CRRT. The nutrition impact of nonintentional calories delivered as citrate, lactate, and glucose during CRRT must be considered. Quantifying nitrogen balance is not feasible during CRRT. Protein delivery should be increased by 25% to compensate for losses in the effluent. Fats are not removed by CRRT and should not be adapted during CRRT. Electrolyte disturbances are frequently present and should be treated accordingly. Vitamins B1, B6, B9, and C are lost in the effluent and should be adapted to the effluent dose. Trace elements, with the exception of selenium, are not cleared in relevant quantities. Manganese accumulation is of concern because of potential neurotoxicity.

Conclusion

Current recommendations regarding nutrition support in pediatric CRRT must be extrapolated from adult studies. Recommendations are provided, based on the weak level of evidence. Additional research on this topic is warranted.

Chinese guidelines for the assessment and provision of nutrition support therapy in critically ill children

BACKGROUND

This document represents the first evidence-based guidelines to describe best practices in nutrition therapy in critically ill children (> 1 month and < 18 years), who are expected to require a length of stay more than 2 or 3 days in a Pediatric Intensive Care Unit admitting medical patients domain.

METHODS

A total of 25,673 articles were scanned for relevance. After careful review, 88 studies appeared to answer the pre-identified questions for the guidelines. We used the grading of recommendations, assessment, development and evaluation criteria to adjust the evidence grade based on the quality of design and execution of each study.

RESULTS

The guidelines emphasise the importance of nutritional assessment, particularly the detection of malnourished patients. Indirect calorimetry (IC) is recommended to estimate energy expenditure and there is a creative value in energy expenditure, 50 kcal/kg/day for children aged 1-8 years during acute phase if IC is unfeasible. Enteral nutrition (EN) and early enteral nutrition remain the preferred routes for nutrient delivery. A minimum protein intake of 1.5 g/kg/day is suggested for this patient population. The role of supplemental parenteral nutrition (PN) has been highlighted in patients with low nutritional risk, and a delayed approach appears to be beneficial in this group of patients. Immune-enhancing cannot be currently recommended neither in EN nor PN.

CONCLUSION

Overall, the pediatric critically ill population is heterogeneous, and an individualized nutrition support with the aim of improving clinical outcomes is necessary and important.

Nutrition Considerations in the Pediatric Cardiac Intensive Care Unit Patient

Adequate caloric intake plays a vital role in the course of illness and the recovery of critically ill patients. Nutritional status and nutrient delivery during critical illness have been linked to clinical outcomes such as mortality, incidence of infection, and length of stay. However, feeding practices with critically ill pediatric patients after cardiac surgery are variable. The Pediatric Cardiac Intensive Care Society sought to provide an expert review on provision of nutrition to pediatric cardiac intensive care patients, including caloric requirements, practical considerations for providing nutrition, safety of enteral nutrition in controversial populations, feeding considerations with chylothorax, and the benefits of feeding beyond nutrition. This article addresses these areas of concern and controversy.

Estimation of Resting Energy Expenditure Using Predictive Equations in Critically Ill Children: Results of a Systematic Review

Provision of adequate energy intake to critically ill children is associated with improved prognosis, but resting energy expenditure (REE) is rarely determined by indirect calorimetry (IC) due to practical constraints. Some studies have tested the validity of various predictive equations that are routinely used for this purpose, but no systematic evaluation has been made. Therefore, we performed a systematic review of the literature to assess predictive equations of REE in critically ill children. We systematically searched the literature for eligible studies, and then we extracted data and assigned a quality grade to each article according to guidelines of the Academy of Nutrition and Dietetics. Accuracy was defined as the percentage of predicted REE values to fall within ±10% or ±15% of the measured energy expenditure (MEE) values, computed based on individual participant data. Of the 993 identified studies, 22 studies testing 21 equations using 2326 IC measurements in 1102 children were included in this review. Only 6 equations were evaluated by at least 3 studies in critically ill children. No equation predicted REE within ±10% of MEE in >50% of observations. The Harris-Benedict equation overestimated REE in two-thirds of patients, whereas the Schofield equations and Talbot tables predicted REE within ±15% of MEE in approximately 50% of observations. In summary, the Schofield equations and Talbot tables were the least inaccurate of the predictive equations. We conclude that a new validated indirect calorimeter is urgently needed in the critically ill pediatric population.).

Can energy intake alter clinical and hospital outcomes in PICU?

BACKGROUND & AIMS

Energy is essential for the treatment and recovery of children admitted to Pediatric Intensive Care Units (PICU). There are significant immediate and long-term health consequences of both under- and over-feeding in this population. Energy requirements of critically ill children vary depending on age, nutritional status, sepsis, fever, pharmacotherapy, and duration and stage of critical illness. This study aimed to determine the incidence of over- and under-feeding and to compare hospital outcomes between these feeding categories. Secondary outcomes were collected to describe the association between feeding categories and biochemistries (serum lactate, triglycerides, C-reactive protein).

METHODS

An ethics approved retrospective study of children admitted to PICU was performed. All intubated patients admitted to PICU (2008-2013) were included, except those in which an IC test was not feasible. Data collection included demographics, the primary outcome variable reported as under feeding (<90%MREE), appropriate (MREE ±10%) or overfeeding (>110% MREE) determined through comparison of measured resting energy expenditure (MREE) using indirect calorimetry (IC) to actual energy intake based on predicted basal metabolic rate (PBMR) and clinical outcomes mechanical ventilation and PICU length of stay (LOS). Data were analysed with descriptive methods, ANOVA and linear regression models.

RESULTS

A total of 139 patients aged 10 (range 0.03-204) months were included. Sixty (43%) were female and 77 (55%) were admitted after a surgical procedure. A total of 210 IC tests were conducted showing a statistically significant difference between MREE measurements and PBMR (p = 0.019). Of the 210 measurements, only 26 measures (12.4%) demonstrated appropriate feeding, while 72 (34.3) were underfed and 112 (53.3%) were overfed. Children who were overfed had significantly longer PICU LOS (median 45.5, IQR 47.8 days) compared to those children in the appropriately fed (median 21.0, IQR 54.5 days), and underfed groups (median 16.5, IQR 21.3 days). There was a mean difference between the over and under feeding category and ventilation days after adjusting for age and PRISM score (p = 0.026), suggesting decreased mechanical ventilation days for underfed. Children who were underfed had significantly higher CRP (median 75.5, IQR 152.8 mg/L) compared to those children in the appropriately fed (median 57.8, IQR 90.9 mg/L) and overfed groups (median 22.4, IQR 56.2 mg/L).

CONCLUSIONS

This retrospective study confirms that estimations of energy expenditure in critically ill children are inaccurate leading to unintended under and overfeeding. Importantly under feeding seems to be associated with fewer mechanical ventilation days and PICU LOS. Further research is required to elucidate the role of optimal nutrition in altering clinical variables in this population.

Underweight Status Is an Independent Predictor of In-Hospital Mortality in Pediatric Patients on Extracorporeal Membrane Oxygenation

BACKGROUND

Malnutrition is associated with an increased risk of mortality in patients admitted to the intensive care unit. Children requiring extracorporeal membrane oxygenation (ECMO) support represent an extremely ill subset of this population. There is a lack of data on the impact of nutrition state on survival in this cohort. We examined the association between being underweight and in-hospital mortality among children supported with ECMO.

MATERIALS AND METHODS

This article reports on an observational retrospective cohort study performed among neonatal and pediatric patients supported with ECMO in a tertiary children's hospital from May 1996 through June 2013. Nutrition status on intensive care unit admission was defined with z scores on weight for length and body mass index.

RESULTS

Patients (N = 491) had a median age of 31 days (interquartile range, 2-771): 24.4% were underweight, and 8.9% were obese. During ECMO support, 88.3% received total parenteral nutrition, and 30.3% received enteral nutrition. Median maximum energy intake while receiving ECMO was 82 kcal/kg/d (interquartile range, 54.7-105). Multiple logistic regression showed that underweight status was associated with increased predicted odds of in-hospital mortality when compared with normal weight (odds ratio: 1.99, 95% confidence interval: 1.21-3.25, P = .006). Other factors associated with increased odds of mortality included extracorporeal cardiopulmonary resuscitation and the need for continuous renal replacement therapy.

CONCLUSION

Underweight status was an independent predictor for in-hospital mortality in our cohort of pediatric ECMO patients. Prospective studies evaluating the impact of metabolic state of children on ECMO should further define this relationship.

Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Pediatric Critically Ill Patient: Society of Critical Care Medicine and American Society for Parenteral and Enteral Nutrition

This document represents the first collaboration between two organizations, American Society of Parenteral and Enteral Nutrition and the Society of Critical Care Medicine, to describe best practices in nutrition therapy in critically ill children. The target of these guidelines is intended to be the pediatric (> 1 mo and < 18 yr) critically ill patient expected to require a length of stay greater than 2 or 3 days in a PICU admitting medical, surgical, and cardiac patients. In total, 2,032 citations were scanned for relevance. The PubMed/Medline search resulted in 960 citations for clinical trials and 925 citations for cohort studies. The EMBASE search for clinical trials culled 1,661 citations. In total, the search for clinical trials yielded 1,107 citations, whereas the cohort search yielded 925. After careful review, 16 randomized controlled trials and 37 cohort studies appeared to answer one of the eight preidentified question groups for this guideline. We used the Grading of Recommendations, Assessment, Development and Evaluation criteria to adjust the evidence grade based on assessment of the quality of study design and execution. These guidelines are not intended for neonates or adult patients. The guidelines reiterate the importance of nutritional assessment, particularly the detection of malnourished patients who are most vulnerable and therefore potentially may benefit from timely intervention. There is a need for renewed focus on accurate estimation of energy needs and attention to optimizing protein intake. Indirect calorimetry, where feasible, and cautious use of estimating equations and increased surveillance for unintended caloric underfeeding and overfeeding are recommended. Optimal protein intake and its correlation with clinical outcomes are areas of great interest. The optimal route and timing of nutrient delivery is an area of intense debate and investigations. Enteral nutrition remains the preferred route for nutrient delivery. Several strategies to optimize enteral nutrition during critical illness have emerged. The role of supplemental parenteral nutrition has been highlighted, and a delayed approach appears to be beneficial. Immunonutrition cannot be currently recommended. Overall, the pediatric critical care population is heterogeneous, and a nuanced approach to individualizing nutrition support with the aim of improving clinical outcomes is necessary.

Timing of the initiation of parenteral nutrition in critically ill children

PURPOSE OF REVIEW

To review the current literature evaluating clinical outcomes of early and delayed parenteral nutrition initiation among critically ill children.

RECENT FINDINGS

Nutritional management remains an important aspect of care among the critically ill, with enteral nutrition generally preferred. However, inability to advance enteral feeds to caloric goals and contraindications to enteral nutrition often leads to reliance on parenteral nutrition. The timing of parenteral nutrition initiation is varied among critically ill children, and derives from an assessment of nutritional status, energy requirements, and physiologic differences between adults and children, including higher nutrient needs and lower body reserves. A recent randomized control study among critically ill children suggests improved clinical outcomes with avoiding initiation of parenteral nutrition on day 1 of admission to the pediatric ICU.

SUMMARY

Although there is no consensus on the optimal timing of parenteral nutrition initiation among critically ill children, recent literature does not support the immediate initiation of parenteral nutrition on pediatric ICU admission. A common theme in the reviewed literature highlights the importance of accurate assessment of nutritional status and energy expenditure in deciding when to initiate parenteral nutrition. As with all medical interventions, the initiation of parenteral nutrition should be considered in light of the known benefits of judiciously provided nutritional support with the known risks of artificial, parenteral feeding.

Implementation of Nutrition Support Guidelines May Affect Energy and Protein Intake in the Pediatric Intensive Care Unit

BACKGROUND

Critically ill children are at risk of developing malnutrition, and undernutrition is a risk factor for morbidity and mortality.

OBJECTIVE

The study evaluated changes in the energy and protein intake before and after implementation of nutrition support (NS) guidelines for a pediatric critical care unit (PICU).

DESIGN

This retrospective study documented energy and protein intake for the first 8 days of PICU stay. Basal metabolic rate and protein needs were estimated by Schofield and American Society for Parenteral and Enteral Nutrition Guidelines, respectively.

PARTICIPANTS/SETTING

Three hundred thirty-five children from August to December 2012 (pre-implementation) and 185 from October to December 2013 (post-implementation).

INTERVENTION

Implementation of NS Guidelines.

MAIN OUTCOME MEASURES

Changes in actual energy and protein intake in the post- compared with the pre-Implementation period.

STATISTICAL ANALYSIS PERFORMED

Unpaired t tests, Pearson's χ(2) (unadjusted analysis) were used. Logistic regressions were used to estimate odds ratios and 95% confidence intervals for protein and energy intake, adjusted for age, sex, and Pediatric Risk of Mortality score.

RESULTS

After the implementation of guidelines, significant improvements were seen during days 5 through 8 in energy intake among children 2 years of age and older, and in protein intake in both age groups (P<0.05). For the 8-day period, statistically or clinically significant improvements occurred in the cumulative protein deficit/kg/day, as follows: younger than 2-year-olds, -1.5±0.7 g/kg/day vs -1.3±0.8 g/kg/day, P=0.02; 2-year-olds or older, -1.0±0.6 g/kg/day vs -0.7±0.8 g/kg/day, P=0.01; and for the energy deficit/kg/d in 2-year-olds and older, -17.2±13.6 kcal/kg/day vs -13.3±18.1 kcal/kg/day, unpaired t test, P=0.07, in the pre- vs post-implementation period, respectively.

CONCLUSIONS

The implementation of NS guidelines was associated with improvements in total energy in 2-year-olds and older and protein in younger than 2 and 2 years and older children by days 5 through 8, and protein deficits were significantly lower in the post- vs the pre-implementation period. The implementation of NS guidelines may have had a positive effect on improving NS in critically ill children.

Nutritional status, metabolic state and nutrient intake in children with bronchiolitis

Nutrition has a coadjuvant role in the management of children with acute diseases. We aimed to examine nutritional status, macronutrient requirements and actual macronutrient delivery in bronchiolitis. The nutritional status was classified according to WHO criteria and resting energy expenditure (MREE) was measured using an indirect calorimeter. Bland-Altman analysis was used to examine the agreement between MREE and estimated energy expenditure (EEE) with standard equations. Based on the ratio MREE/EEE in relation to Schofield equation on admission, we defined the subjects' metabolic status. A total of 35 patients were enrolled and 46% were malnourished on admission, and 25.8% were hypermetabolic, 37.1% hypometabolic and 37.1% normometabolic. We performed a 24-h recall in 10 children and 80% were overfed (AEI: MREE >120%). Mean bias (limits of agreement) with MREE was 8.9 (-73.9 to 91.8%) for Schofield; 61.0 (-41 to 163%) for Harris-Benedict; and 9.9 (-74.4 to 94.2%) for FAO-WHO equation. Metabolism of infants with bronchiolitis is not accurately estimated by equations.

Energy and Protein Delivery in Overweight and Obese Children in the Pediatric Intensive Care Unit

BACKGROUND

Early and optimal energy and protein delivery have been associated with improved clinical outcomes in the pediatric intensive care unit (PICU). Overweight and obese children in the PICU may be at risk for suboptimal macronutrient delivery; we aimed to describe macronutrient delivery in this cohort.

METHODS

We performed a retrospective study of PICU patients ages 2-21 years, with body mass index (BMI) ≥85th percentile and >48 hours stay. Nutrition variables were extracted regarding nutrition screening and assessment, energy and protein prescription, and delivery.

RESULTS

Data from 83 patient encounters for 52 eligible patients (52% male; median age 9.6 [5-15] years) were included. The study cohort had a longer median PICU length of stay (8 vs 5 days, P < .0001) and increased mortality rate (6/83 vs 182/5572, P = .045) than concurrent PICU patient encounters. Detailed nutrition assessment was documented for 60% (50/83) of patient encounters. Energy expenditure was estimated primarily by predictive equations. Stress factor >1.0 was applied in 44% (22/50). Median energy delivered as a percentage of estimated requirements by the Schofield equation was 34.6% on day 3. Median protein delivered as a percentage of recommended intake was 22.1% on day 3.

CONCLUSIONS

The study cohort had suboptimal nutrition assessments and macronutrient delivery during their PICU course. Mortality and duration of PICU stay were greater when compared with the general PICU population. Nutrition assessment, indirect calorimetry-guided energy prescriptions, and optimizing the delivery of energy and protein must be emphasized in this cohort. The impact of these practices on clinical outcomes must be investigated.

Do PICU patients meet technical criteria for performing indirect calorimetry?

BACKGROUND & AIMS

Indirect calorimetry (IC) is considered gold standard for assessing energy needs of critically ill children as predictive equations and clinical status indicators are often unreliable. Accurate assessment of energy requirements in this vulnerable population is essential given the high risk of over or underfeeding and the consequences thereof. The proportion of patients and patient days in pediatric intensive care (PICU) for which energy expenditure (EE) can be measured using IC is currently unknown. In the current study, we aimed to quantify the daily proportion of consecutive PICU patients who met technical criteria to perform indirect calorimetry and describe the technical contraindications when criteria were not met.

METHODS

Prospective, observational, single-centre study conducted in a cardiac and general PICU. All consecutive patients admitted for at least 96 h were included in the study. Variables collected for each patient included age at admission, admission diagnosis, and if technical criteria for indirect calorimetry were met. Technical criteria variables were collected within the same 2 h each morning and include: provision of supplemental oxygen, ventilator settings, endotracheal tube (ETT) leak, diagnosis of chest tube air leak, provision of external gas support (i.e. nitric oxide), and provision of extracorporeal membrane oxygenation (ECMO).

RESULTS

288 patients were included for a total of 3590 patient days between June 2014 and February 2015. The main reasons for admission were: surgery (cardiac and non-cardiac), respiratory distress, trauma, oncology and medicine/other. The median (interquartile range) patient age was 0.7 (0.3-4.6) years. The median length of PICU stay was 7 (5-14) days. Only 34% (95% CI, 32.4-35.5%) of patient days met technical criteria for IC. For patients less than 6 months of age, technical criteria were met on significantly fewer patient days (29%, p < 0.01). Moreover, 27% of patients did not meet technical criteria for IC on any day during their PICU stay. Most frequent reasons for why IC could not be performed included supplemental oxygen, ECMO, and ETT leak.

CONCLUSIONS

In the current study, technical criteria to perform IC in the PICU were not met for 27% of patients and were not met on 66% of patient days. Moreover, criteria were met on only 29% of days for infants 6 months and younger where children 24 months of age and older still only met criteria on 40% of patient days. This data represents a major gap in the feasibility of current recommendations for assessing energy requirements of this population. Future studies are needed to improve methods of predicting and measuring energy requirements in critically ill children who do not meet current criteria for indirect calorimetry.

Association between nutritional status and outcomes in critically-ill pediatric patients - a systematic review

OBJECTIVES

To systematically review the evidence about the impact of nutritional status in critically-ill pediatric patients on the following outcomes during hospitalization in pediatric intensive care units: length of hospital stay, need for mechanical ventilation, and mortality.

DATA SOURCE

The search was carried out in the following databases: Lilacs (Latin American and Caribbean Health Sciences), MEDLINE (National Library of Medicine United States) and Embase (Elsevier Database). No filters were selected.

RESULTS

A total of seven relevant articles about the subject were included. The publication period was between 1982 and 2012. All articles assessed the nutritional status of patients on admission at pediatric intensive care units and correlated it to at least one assessed outcome. A methodological quality questionnaire created by the authors was applied, which was based on some references and the researchers' experience. All included studies met the quality criteria, but only four met all the items.

CONCLUSION

The studies included in this review suggest that nutritional depletion is associated with worse outcomes in pediatric intensive care units. However, studies are scarce and those existing show no methodological homogeneity, especially regarding nutritional status assessment and classification methods. Contemporary and well-designed studies are needed in order to properly assess the association between children's nutritional status and its impact on outcomes of these patients.

A Nursing Survey on Nutritional Care Practices in French-Speaking Pediatric Intensive Care Units: NutriRéa-Ped 2014

OBJECTIVES

Malnutrition in critically ill children contributes to morbidity and mortality. The French-speaking pediatric intensive care nutrition group (NutriSIP) aims to promote optimal nutrition through education and research.

METHODS

The NutriSIP-designed NutriRéa-Ped study included a cross-sectional survey. This 62-item survey was sent to the nursing teams of all of the French-speaking pediatric intensive care units (PICUs) to evaluate nurses' nutrition knowledge and practices. One nurse per PICU was asked to answer and describe the practices of their team.

RESULTS

Of 44 PICUs, 40 responded in Algeria, Belgium, Canada, France, Lebanon, Luxemburg, and Switzerland. The majority considered nutrition as a priority care but only 12 of the 40 (30%) had a nutrition support team, 26 of the 40 (65%) had written nutrition protocols, and 19 of 39 (49%) nursing teams felt confident with the nutrition goals. Nursing staff generally did not know how to determine nutritional requirements or to interpret malnutrition indices. They were also unaware of reduced preoperative fasting times and fast-track concepts. In 17 of 35 (49%) PICUs, the target start time for enteral feeding was within the first 24 hours; however, frequent interruptions occurred because of neuromuscular blockade, fasting for extubation or surgery, and high gastric residual volumes. Combined pediatric neonatal intensive care units were less likely to perform systematic nutritional assessment and to start enteral nutrition rapidly.

CONCLUSIONS

We found a large variation in nursing practices around nutrition, exacerbated by the lack of nutritional guidelines but also because of the inadequate nursing knowledge around nutritional factors. These findings encourage the NutriSIP to improve nutrition through focused education programs and research.

Nutrition: A Primary Therapy in Pediatric Acute Respiratory Distress Syndrome

Appropriate nutrition is an essential component of intensive care management of children with acute respiratory distress syndrome (ARDS) and is linked to patient outcomes. One out of every two children in the pediatric intensive care unit (PICU) will develop malnutrition or have worsening of baseline malnutrition and present with specific micronutrient deficiencies. Early and adequate enteral nutrition (EN) is associated with improved 60-day survival after pediatric critical illness, and, yet, despite early EN guidelines, critically ill children receive on average only 55% of goal calories by PICU day 10. Inadequate delivery of EN is due to perceived feeding intolerance, reluctance to enterally feed children with hemodynamic instability, and fluid restriction. Underlying each of these factors is large practice variation between providers and across institutions for initiation, advancement, and maintenance of EN. Strategies to improve early initiation and advancement and to maintain delivery of EN are needed to improve morbidity and mortality from pediatric ARDS. Both, over and underfeeding, prolong duration of mechanical ventilation in children and worsen other organ function such that precise calorie goals are needed. The gut is thought to act as a "motor" of organ dysfunction, and emerging data regarding the role of intestinal barrier functions and the intestinal microbiome on organ dysfunction and outcomes of critical illness present exciting opportunities to improve patient outcomes. Nutrition should be considered a primary rather than supportive therapy for pediatric ARDS. Precise nutritional therapies, which are titrated and targeted to preservation of intestinal barrier function, prevention of intestinal dysbiosis, preservation of lean body mass, and blunting of the systemic inflammatory response, offer great potential for improving outcomes of pediatric ARDS. In this review, we examine the current evidence regarding dose, route, and timing of nutrition, current recommendations for provision of nutrition to children with ARDS, and the current literature for immune-modulating diets for pediatric ARDS. We will examine emerging data regarding the role of the intestinal microbiome in modulating the response to critical illness.

Controversies in nutritional support for critically ill children

Nutritional support for critically ill infants and children is of paramount importance and can greatly affect the outcome of these patients. The energy requirement of children is unique to their size, gestational age, and physiologic stress, and the treatment algorithms developed in adult intensive care units cannot easily be applied to pediatric patients. This article reviews some of the ongoing controversial topics of fluid, electrolyte, and nutritional support for critically ill pediatric patients focusing on glycemic control and dysnatremia. The use of enteral and parenteral nutrition as well as parenteral nutritional-associated cholestasis will also be discussed.

Metabolic assessment and individualized nutrition in children dependent on mechanical ventilation at home

OBJECTIVE

To evaluate the nutritional and metabolic status and body composition of children on long-term mechanical ventilation using a home-based model.

STUDY DESIGN

Children on home mechanical ventilation, for at least 12 hours a day, were eligible. We performed anthropometry, bioelectrical impedance analysis (BIA), actual energy intake (AEI), and indirect calorimetry in the subject's home. Agreement between measured energy expenditure (MEE) from indirect calorimetry, and estimated energy expenditure by the Schofield equation and a novel volumetric carbon dioxide production-based equation was examined. Agreement between fat mass estimates from anthropometry and BIA was examined and compared with population norms.

RESULTS

We enrolled 20 children, 11 (55%) male; mean age 8.4 years (SD 4.8). Mean weight for age z-score was -0.26 (SD 1.48); 9/20 had z-scores <-1 or >+1. Thirteen were underfed (AEI:MEE <90%) or overfed (AEI:MEE >110%); 11 of 19 had protein intake that was less than recommended by guidelines. Fifteen subjects were hypo- or hypermetabolic. Mean (SD) fat mass % was 33.6% (8.6) by anthropometry, which was significantly greater than matched population norms (mean 23.0%, SD 6.1, P < .001). The estimated energy expenditure by a volumetric carbon dioxide production-based equation was in stronger agreement with the MEE than the Schofield equation (mean bias 0.06%, limits -15.98% to 16.16% vs mean bias -1.31%, limits -74.3% to 72%, respectively). BIA and anthropometric fat mass values were not in agreement.

CONCLUSION

A majority of children on home ventilation are characterized by malnutrition, altered metabolic status, and suboptimal macronutrient intake, in particular low protein intake. A multidisciplinary home-based model facilitates individualized energy and protein delivery and may improve outcomes in this cohort.

Fulfilling caloric demands according to indirect calorimetry may be beneficial for post cardiac arrest patients under therapeutic hypothermia

INTRODUCTION

We sought to investigate the energy requirements for patients under therapeutic hypothermia, and the relationship of energy fulfillment to patient outcome.

PATIENTS AND METHODS

Adult patients admitted to our ICU after successful resuscitation from cardiac arrest for post resuscitation therapeutic hypothermia from April, 2012 to March, 2014 were enrolled. Body temperature was managed using the surface cooling device (Arctic Sun(®), IMI). Calorimeter module on the ventilator (Engström carestation(®), GE) was used for indirect calorimetry. Energy expenditure (EE) and respiratory quotient (RQ) were recorded continuously, as the average of the recent 2h. Measurements were started at the hypothermic phase and continued until the rewarming was completed. Cumulative energy deficit was calculated as the sum of difference between EE and daily energy provision for the 4 days during hypothermia therapy.

RESULTS

Seven patients were eligible for analysis. Median EE for the hypothermic phase (day 1) was 1557.0kcald(-1). EE was elevated according with the rise in body temperature, reaching 2375kcald(-1) at normothermic phase. There was significant association between cumulative energy deficit and the length of ICU stay, among patients with good neurologic recovery (cerebral performance category (CPC): 1-3).

CONCLUSION

The EE for patients under therapeutic hypothermia was higher than expected. Meeting the energy demand may improve patient outcome, as observed in the length of ICU stay for the present study. A larger, prospective study is awaited to validate the results of our study.

Nutrition algorithms and bedside nutrient delivery practices in pediatric intensive care units: an international multicenter cohort study

BACKGROUND

Enteral nutrition (EN) delivery is associated with improved outcomes in critically ill patients. We aimed to describe EN practices, including details of algorithms and individual bedside practices, in pediatric intensive care units (PICUs).

METHODS

Available EN algorithm details from 31 international PICUs were obtained. Daily nutrient intake data from 524 mechanically ventilated patients, 1 month to 18 years old, were prospectively documented, including EN delivery, adjunct therapies, and energy prescription. Practices associated with higher percentage adequacy of EN delivery were determined by regression analysis.

RESULTS

Nine EN algorithms were available. All algorithms defined advancement and EN intolerance; 7 of 9 defined intolerance by gastric residual volume; 3 of 9 recommended nutrition screening and fasting guidelines. Few elements were in agreement with the American Society for Parenteral and Enteral Nutrition and the European Society of Paediatric Gastroenterology, Hepatology, and Nutrition guidelines. Of the 341 patients who received EN exclusively 32.9% received ≥66.6% of prescribed energy on day 7. Percentage adequacy of EN delivered was inversely associated with days to EN initiation (-8.92; P < .001) and hours per EN interruption (-1.65; P = .001) and was not associated with the use of algorithms, promotility agents, or postpyloric feeding.

CONCLUSIONS

A minority of PICUs employ EN algorithms; recommendations were variable and not in agreement with national guidelines. Optimal EN delivery was achieved in less than one-third of our cohort. EN adjunct therapies were not associated with increased EN delivery. Studies aimed at promoting early EN and decreasing interruptions may optimize energy delivery in the PICU.

Current applications of metabolic monitoring in the pediatric intensive care unit

Delivery of adequate nutrients during illness to counteract the metabolic stress response and facilitate healing and tissue repair is an important goal in the care of critically ill children. With recent advances in technology, accurate minute-to-minute gas exchange and energy expenditure measurements are now available in intensive care units. The bedside availability of these devices may allow a titrated approach to energy delivery for patients, ushering in a new era of individualized nutrition therapy. Basic concepts, available monitoring devices, indications, pitfalls, and bedside application of metabolic monitoring are discussed in this article.

Validation of the V(max) metabolic cart in a simulated pediatric model

BACKGROUND

The ability to accurately measure resting energy expenditure (REE) using indirect calorimetry, often referred to as the "gold standard" in nutrition needs assessment, is important given the well-established positive correlation between patient outcome and proportion of the nutrition goal met. While many studies have been done to compare various metabolic carts with one another, the literature lacks a large simulator-based validation of any metabolic cart system.

MATERIALS AND METHODS

In the present study, 8 specifically trained staff members independently conducted 10 simulation trials each using the V(max) Encore metabolic analyzer in conjunction with a metabolic calibration system, which simulates patient metabolic activity, to validate the accuracy of the V(max) Encore across a wide range of simulated metabolic conditions. Testing conditions consisted of incremental adjustments in calibrated gas infusion with a consistently set tidal volume and respiratory rate.

RESULTS

There was a strong, statistically significant correlation between the predicted and actual VO2 and VCO2 data (VO2, R (2) = 0.998; VCO2, R (2) = 0.997). In addition, we observed no significant difference between individuals performing these trials (VO2, P = 1.000, F = 0.021, df = 79; VCO2, P = 1.000, F = 0.030, df = 79).

CONCLUSIONS

This study is the first to report on such a wide spectrum of metabolic activity (50-2000 kcal REE) using a calibrated bench model and validates the accuracy, reproducibility, and use of the V(max) Encore metabolic cart.

Accuracy of a simplified equation for energy expenditure based on bedside volumetric carbon dioxide elimination measurement--a two-center study

BACKGROUND & AIMS

Accurate assessment of resting energy expenditure (REE) and metabolic state is essential to optimize nutrient intake in critically ill patients. We aimed to examine the accuracy of a simplified equation for predicting REE using carbon dioxide elimination (VCO2) values.

METHODS

We conducted a two-center study of metabolic data from mechanically ventilated children less than 18 years of age. Mean respiratory quotient (RQ) from the derivation set (n = 72 subjects) was used to modify the Weir equation to obtain a simplified equation based on VCO2 measurements alone. This equation was then applied to subjects at the second institution (validation dataset, n = 94) to predict resting energy expenditure. Bland-Altman analysis was used to assess the agreement between measured REE values, and REE estimated by the new equation as well as the Schofield equation. We also examined the accuracy of the new equation in classifying patients according to their metabolic state.

RESULTS

Mean respiratory quotient (± SD) of 0.89 ± 0.09 in the derivation set was used to obtain a simplified equation, REE (kcal/day) = 5.534*VCO2 (L/min)*1440. In relation to the measured REE in the validation set, the mean bias (limits of agreement) for the REE predicted by this equation was -0.65% (-14.4-13.1%); and the overall diagnostic accuracy for classifying subjects as hypometabolic or hypermetabolic was 84%. Mean bias (limits) of agreement between measured and Schofield equation estimated REE was -0.1% (-40.5-40.7%).

CONCLUSIONS

A simplified metabolic equation using VCO2 values was superior to the standard equation in estimating REE, and provided a reasonably accurate metabolic classification in mechanically ventilated children. In the absence of indirect calorimetry, bedside VCO2 monitoring could provide valuable continuous metabolic information to guide optimal nutrient intake.

Achieving energy goals at day 4 after admission in critically ill children; predictive for outcome?

BACKGROUND & AIMS

Adequate nutritional intake is essential during pediatric intensive care admission. We investigated whether achievement of energy intake goals at day 4 after admission and route of nutrition were associated with improved outcome.

METHODS

Observational study using prospectively acquired data. Patients receiving enteral and/or parenteral nutrition were included. The energy intake target range at day 4 after admission was 90-110% of resting energy expenditure +10%. Acute malnutrition was defined as weight-for-age <-2 SD. Clinical outcome measures were length of stay, days on ventilator, duration of antibiotics and number of new infections. Data as median (min-max).

RESULTS

Of 325 subjects (age 0.14 (0.0-18.0) year), 19% were acutely malnourished upon admission. Median 86% of energy goals were administered via the enteral route. With enteral energy intake, 7% of patients were fed within the target range, 50% were fed below and 43% were fed above the target range. In a subgroup (n = 223) the acutely malnourished proportion at discharge (26%) was not significantly different from that upon admission (22%). Whether the energy intake was below, within or above the target range did not affect changes in clinical outcome, nor did the route of nutrition.

CONCLUSIONS

Acute malnutrition was highly prevalent upon admission and at discharge. With our nutritional protocol we achieved high rates of (enteral) energy intake. A high percentage of our population received enteral energy above the target energy range. However, there was no association between the amount of energy intake or route of nutrition and clinical outcome.

Early enteral nutrition is associated with lower mortality in critically ill children

BACKGROUND

The purpose of this study was to examine the association of early enteral nutrition (EEN), defined as the provision of 25% of goal calories enterally over the first 48 hours of admission, with mortality and morbidity in critically ill children.

METHODS

We conducted a multicenter retrospective study of patients in 12 pediatric intensive care units (PICUs). We included patients aged 1 month to 18 years who had a PICU length of stay (LOS) of ≥96 hours for the years 2007-2008. We obtained patients' demographics, weight, Pediatric Index of Mortality-2 (PIM2) score, LOS, duration of mechanical ventilation (MV), mortality data, and nutrition intake data in the first 4 days after admission.

RESULTS

We identified 5105 patients (53.8% male; median age, 2.4 years). Mortality was 5.3%. EEN was achieved by 27.1% of patients. Children receiving EEN were less likely to die than those who did not (odds ratio, 0.51; 95% confidence interval, 0.34-0.76; P = .001 [adjusted for propensity score, PIM2 score, age, and center]). Comparing those who received EEN to those who did not, adjusted for PIM2 score, age, and center, LOS did not differ (P = .59), and the duration of MV for those receiving EEN tended to be longer than for those who did not, but the difference was not significant (P = .058).

CONCLUSIONS

EEN is strongly associated with lower mortality in patients with PICU LOS of ≥96 hours. LOS and duration of MV are slightly longer in patients receiving EEN, but the differences are not statistically significant.